You are here:HomeNewsIs this the biggest breakthrough in propulsion since the jet engine?

Is this the biggest breakthrough in propulsion since the jet engine?

November 30, 2012

Hot air passes over the fine piping, plunging to -150C in just 1/100th of a second (credit: Mark Ford et al./Reaction Engines Ltd.)

Reaction Engines Ltd. has announced what is says is the “biggest breakthrough in aerospace propulsion technology since the invention of the jet engine.”

Critical tests have been successfully completed on the key technology for SABRE, an engine that will enable aircraft to reach the opposite side of the world in under four hours, or to fly directly into orbit and return in a single stage, taking off and landing on a runway.

SABRE, an air-breathing rocket engine, uses a combination of jet turbine and rocket technology. Its innovative pre-cooler technology is designed to cool the incoming airstream from over 1,000⁰C to minus 150⁰C in less than 1/100th of a second without blocking with frost.

The recent tests have proven the cooling technology to be frost-free at the crucial low temperature of -150⁰C.

The European Space Agency (ESA) has evaluated the SABRE engine’s pre-cooler heat exchanger on behalf of the UK Space Agency, and has given official validation to the test results:

“The pre-cooler test objectives have all been successfully met and ESA are satisfied that the tests demonstrate the technology required for the SABRE engine development.”

This advanced combined cycle air-breathing SABRE rocket engine enables aircraft to operate easily at speeds of up to five times the speed of sound or fly directly into Earth orbit (credit: Reaction Engines)

The U.K. Minister for Universities and Science, David Willetts said: “This is a remarkable achievement for a remarkable company.

Building on years of unique engineering know-how, Reaction Engines has shown the world that Britain remains at the forefront of technological innovation and can get ahead in the global race. This technology could revolutionize the future of air and space travel.”

Well over 100 test runs, undertaken at Reaction Engines Ltd’s facility in Oxfordshire, integrated the ground-breaking flight-weight cooling technology and frost control system with a jet engine and a novel helium cooling loop, demonstrating the new technologies in the SABRE engine that drive its highly innovative and efficient thermodynamic cycle.

This success adds to a series of other SABRE technology demonstrations undertaken by the company including contra-rotating turbines, combustion chambers, rocket nozzles, and air intakes and marks a major advance towards the creation of vehicles like SKYLON — a new type of reusable space vehicle that will be powered by SABRE engines, designed primarily to transport satellites and cargo into space.

SKYLON is an unpiloted, reusable spaceplane intended to provide reliable, responsive and cost effective access to space. Currently in early development phase, the vehicle will be capable of transporting 15 tonnes of cargo into space. It is the use of SABRE’s combined air-breathing and rocket cycles that enables a vehicle that can take off from a runway, fly direct to earth orbit and return for a runway landing, just like an aircraft. (Credit: Reaction Engines)

“These successful tests represent a fundamental breakthrough in propulsion technology. Reaction Engines’ lightweight heat exchangers are going to force a radical re-think of the design of the underlying thermodynamic cycles of aerospace engines.

These new cycles will open up completely different operational characteristics such as high Mach cruise and low cost, re-usable space access, as the European Space Agency’s validation of Reaction Engines’ SABRE engine has confirmed.

“The SABRE engine has the potential to revolutionize our lives in the 21st century in the way the jet engine did in the 20th Century. This is the proudest moment of my life.”

If this turns out to be successful, it would be the first technological progress in aeronautics after more than 40 years of technological decline. It would not only speed up air travel, but finally get humanity back into space.

I thought it was the sonic boom that killed the Concorde. I can just see the Neo-Luddites coming out in droves and trying to kill this incredible innovation. But, really, has anyone addressed the sonic boom problem? My ears are hurting in anticipation.

this sounds to me like some variation of a vortex tube .it is a tee with no moving parts. hot air in through one opening and cold air out another and hot air out another. i dont know where the condensate goes on the cold side or if it is separated and leaves with the heat pipe discharge. if that is the case you would be left with cold dry air and no machinery to deal with

The cycle is driving me nuts. OK, put aside frosting and other condensation problems. The air enters the intake before the compressor. It is slowed to subsonic speeds (good for the flameholders later) and since the process is essentially adiabatic (ideally isentropic), it gets hot. Very hot and hypersonic speeds. That intake process has also exerted noticeable drag on the engine in the process but because it’s an adiabatic process we haven’t actually lost any total energy yet. Now comes the fun part. We suck the heat out of the air, lowering it’s internal energy/enthalpy and we dump that heat overboard with some excess hydrogen. OK, energy lost, but we’ve still paid the penalty of decelerating and compressing the air in stage one. Now we complete the Brayton cycle by running it through a combustion chamber and past a turbine to run the first stage compressor. Now we can’t have added too much energy in the combustion phase or the turbine fails, but it still needs to be hotter than the 1000C inlet temp or we haven’t actually produced any useful thrust. Is there an afterburner stage that avoids the turbine problem? How much energy have we lost from the intercooler?

I recall that the SR-71, which could exceed Mach 5, was nearly all fuel tank. No matter how you slice it, cutting through air at that high a mach takes a tremendous amount of fuel. Of course, if you can achieve escape velocity and get above most of the atmosphere before your fuel runs out, that’s a plan.

As far as I can tell from this article, there is no engine yet. They have only tested components of the engine. Talk to me when a SABRE engine is in a real plane and tested in the real atmosphere. Otherwise the press release sounds like your typical hype-building message in advance of another round of financing.

Obviously passenger comfort will be taken into account on super long distance flights, the main breakthrough is for space cargo. Capitalizing near earth activities is what is needed to jump start more ambitious lunar and Martian colonies, plus asteroid mining. If it takes six or eight hours to get to china, as opposed to four and a half, I’m sure it will still be attractive. Especially to business travelers. I can’t wait to here what the savings will be in terms of space cargo.

here is what I do not understand about the demonstrated technology. This is more or less a jet engine with a cooling equipment right? It still needs fresh air coming from outside and exhaust the air back again.

Then how will it accomplish high orbit jobs including putting a satellite into orbit? At this heights the air intake can not be enough to run a jet engine???

Watch the video (at 1 min 40), once the main engines are out of their working zone, a conventional rocket engine at the back of Skylon can be ignited for the final additional thrust needed for orbital rendezvous (alternatively, you can use the main engines fed by liquid oxygen like in a classical rocket engine).

The big novelty here is to have the engine fed by oxygen taken from outside and not embarked as fuel in its liquid form. The breakthrough is the super cooler encasing the engine whose main purpose is to have the engine take high pressured oxygen (through super cooling) as intake for the reactor. Then you have consistent high thrust without over heating and most important, without needing liquid oxygen (substantial part of the fuel payload) but just liquid hydrogen as embarked fuel.

My wife and I travel to China about every 18 months.
It takes about a day and a half total travel time and all that sitting
And squirming in airplane seats really takes a toll.
If we could really make the same trip in 4 hours, it would be awesome!
The tickets would probably cost a lot more, but it would be worth it.

It’s acceleration that presses you into the seat, not velocity. Just because the engine is capable of enough thrust to overcome the drag at Mach 5, doesn’t mean they’re going to crank it up to 100% on takeoff. I’m sure they’d be capable of bringing the craft up to Mach 5 in a slower way, at accelerations no worse than the takeoff of a regular passenger jet.

Of course, but show me the calculations to get around the world in 3.5 hours or your post is useless. How much is 80% of “squashing” acceleration, how much is 80% of “uncomfortable” acceleration, and most importantly, how long will you be enduring it during it? don’t forget the diagonal ascent and descent (respectively) to and from orbit will also increase the distance traveled in your calculations not to mention add and subtract (non respectively) gravity itself to the resultant acceleration. I’ll cut you some slack and let you ignore the effects of atmospheric drag and, sure, you can add the earth rotational speed to cut you some distance, but only AFTER you’re on orbit (unless you actually consider the atmosphere). But try going the OTHER WAY (i.e. East) around the earth and see how much less comfort you’ll be suffering to achieve such timings then tell us what happens when your destination is less than 12h to the east. If you want to ace this, then also add how far from that point it is not worthy anymore.
We will be waiting for your pertinent conclusions.

If the craft accelerates constantly longitudinally at 1G, then it reaches Mach 5 in a little over two and a half minutes… At takeoff, the passengers will experience a net force of 2G, pushing them into their seats for a few minutes. 2G is not intolerable, but the acceleration could of course be spread over several more minutes, making it much softer. I don’t think the idea is to go into orbit, when using it as a normal passenger plane, but I don’t know.

Good point, they do seem to imply mutual exclusivity there — “OR go into orbit” — so you may be right… but I would suppose it would save quite a bit on fuel for long distances; and since this is a hybrid of rocket fuel, it is even more expensive… so every drop counts :-D

you people are like my family while watching a movie they stare at the tv but never see a damn thing i some times wonder why the hell they even bother to watch i will explain first the engine uses both jet and rocket technology the fuel
is hydrogen in order to use atmosphere in the plane the oxygen needs to be cooled why because at mach 5 air temperature reaches 1000 degrees
centigrade would melt jet engines the reason for the cooler now you need much less oxygen once you leave the atmosphere you then use on
board oxygen all of this was for reducing the amount of oxygen need on board the space shuttle need that gigantic tank for you guessed it oxygen to fly from new york to Paris in atmosphere heat becomes a problem again
for the shell of the ship that`s why they studied the SR 71 blackbird it did mach 5 in the atmosphere reaction engine are taking clues from that research after mach 5 you need mach 25 to leave earths gravity and reach space now you use the rocket engine with the on board oxygen we saved oxygen the main goal save weight space the only questions are weight to thrust and what will it take to get in to space my math is not that good but with a little help i could do the math i was dreaming about doing this from the time i was twenty i am 3 times that age now i was using both jet and rocket engines and know i would have weight problems without even doing the math he cut the weight problems in half just with his new type of engine now for the heat shielding it would take more work than i want to put in here but there some new breakthroughs that make that a non problem so lets recap carrying an oxidizer takes most of the weight and space in all of todays rockets without that wasted weight and space with additional help from aerodynamics your cost are reduced even more the precooler makes a ssto possible much of what you people sound good but you are talking out of your collective asses its clear you don`t understand whats going on

Uh, less than 2G – the acceleration’s (approximately) at 90* to gravity, so vector addition will give roughly 1.4G to the seat of the pants – a lot of lifts (elevators) put you through almost as much. Hell, one of my bikes puts me through that much!

For passenger use, it wouldn’t need to go into orbit, just take a ballistic trajectory leaving the atmosphere to minimize drag (and thus fuel use), think V2s and ICBMs, neither reach escape nor orbital velocity – people might have to get used to weightlessness for a significant part of the flight, though.

No, if the acceleration were completely orthogonal to gravity then the total acceleration would be sqrt(2*2 + 1*1)=sqrt(5)=2.23g. The acceleration is reduced only to the extent that the craft is climbing and the acceleration is in partial opposition to gravity. See gravity drag.

What is the point of your comment? If you’re as smart as you’re trying to sound, there’s no reason for your comment. Therefore, I’ll assume you need some help.

Here’s a very basic, quick analysis:
Assume a constant cruising speed of 1500 m/s (about Mach 5 at 30 km altitude). Assume your destination is on the other side of the planet approximately 20,000 km away (about half the circumference of the earth at the equator). Assume constant acceleration during take-off and landing of 1g.

To get from a stop to cruising speed (and vice-versa) it will take 153 seconds – 1500 m/s div 9.806 m/s^2 – and you’ll cover a total of approximately 230 km over both. That leaves 19,770 km at cruising speed, which will take about 3.66 hours.

So… about 2.5 minutes speeding up, 3.66 hours cruising, and 2.5 minutes going down. You’d still be under 4 hours if you either doubled the acceleration times or increased the distance by 1,000 km.

No problem at all. Do you really think a responsible company would make this kind of irresponsible claims? Bad marketing that would be. Do you think it is a coincidence your back of the envelope calculation got you to 3.9 hours?

I for one could not ever endeavor such a hopeless task. It is bound to failure since there is no sound capable of such heights. But, since you mention, even if perhaps it was not your goal, you do manage to sound quite smart.

Why do you think the claim is irresponsible? This company is not the first to make that claim, and technology in general is progressing to the point where it may be feasible. For example, the X-51 has shown promise with advancing scramjet technology.

@Melagara: Google David Adair. He’s got a book out called A fall from space, that cronicals the problems qt NASA. His company commercializes NASA technology. He also talks about his experiences at area 51.